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3 years ago

I need help with this

Chemistry

2 answers:

notka56 [123]3 years ago

8 0

Answer: B

Explanation: All you have to do to find out if an equation is balanced is count the number of atoms on each side. To be balanced, they must be equal.

In case you didn’t know: The number in front of an element or compound means that you will multiply. For instance, 2AlBr3 would have 2 Al atoms and 6 Br atoms. The subscript number just means how many atoms there are in that compound.

marshall27 [118]3 years ago

7 0

What is it you need help on? there is nothing here????

ANSWER:

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How many atoms are in 5 mole of water?<br> Steps

Vladimir79 [104]

Answer: 3.01 x 10^24 atoms

Explanation:

Based on Avogadro's law:

1 mole of any substance has 6.02 x 10^23 atoms

So, 1 mole of water = 6.02 x 10^23 atoms

5 moles of water = Z atoms

To get the value of Z, cross multiply

Z x 1 mole = (6.02 x 10^23 atoms x 5 moles)

Z•mole = 30.1 x 10^23 atoms•mole

Divide both sides by 1 mole

Z•mole/1 mole = 30.1 x 10^23 atoms•mole/ 1 mole

Z = 30.1 x 10^23 atoms

[Place the value of Z in standard form]

Z = 3.01 x 10^24 atoms

Thus, there are 3.01 x 10^24 atoms in 5 mole of water

3 0

3 years ago

What is the hydrogen ion concentration of a solution with a pH of 2.0?

aliina [53]

Answer:

Knowing others is intelligence; knowing yourself is true wisdom. mastering others is strength; mastering yourself is true power. if you realize that you have enough, you are truly rich, "And the cause of not following your heart, is in spending the rest of your life wishing you had."

Explanation:

I need points so SORRY!

8 0

3 years ago

HRISTINA HERRERA: Attempt 1

Lunna [17]

Answer:

7.5 g of hydrogen gas reacts with 50.0 g oxygen gas to form 57.5 g of water.

Explanation:

Here we have the check if the mass of the reactants is equal to the mass of the products.

Reactants

$7.5+50=57.5\ \text{g}$

Products

$57.5\ \text{g}$

The data is consistent with the law of conservation of matter.

Reactants

$50+243=293\ \text{g}$

Products

$206+97=303\ \text{g}$

The data is not consistent with the law of conservation of matter.

Reactant

$17.7+34.7=52.4\ \text{g}$

Products

$62.4\ \text{g}$

The data is not consistent with the law of conservation of matter.

Only the first data is consistent with the law of conservation of matter.

8 0

3 years ago

A 50/50 blend of engine coolant and water (by volume) is usually used in an automobile's engine cooling system. If a car's cooli

Diano4ka-milaya [45]

Answer:

$\large \boxed{109.17 \, ^{\circ}\text{C}}$

Explanation:

Data:

50/50 ethylene glycol (EG):water

V = 4.70 gal

ρ(EG) = 1.11 g/mL

ρ(water) = 0.988 g/mL

Calculations:

The formula for the boiling point elevation ΔTb is

$\Delta T_{b} = iK_{b}b$

i is the van’t Hoff factor — the number of moles of particles you get from 1 mol of solute. For EG, i = 1.

1. Moles of EG

$\rm n = 0.50 \times \text{4.70 gal} \times \dfrac{\text{3.785 L}}{\text{1 gal}} \times \dfrac{\text{1000 mL}}{\text{1 L}} \times \dfrac{\text{1.11 g}}{\text{1 mL}} \times \dfrac{\text{1 mol}}{\text{62.07 g}} = \text{159 mol}$

2. Kilograms of water

$m = 0.50 \times \text{4.70 gal} \times \dfrac{\text{3.785 L}}{\text{1 gal}} \times \dfrac{\text{998 g}}{\text{1 L}} \times \dfrac{\text{1 kg}}{\text{1000 g}} = \text{8.88 kg}$

3. Molal concentration of EG

$b = \dfrac{\text{159 mol}}{\text{8.88 kg}} = \text{17.9 mol/kg}$

4. Increase in boiling point

$\rm \Delta T_{b} = iK_{b}b = 1 \times 0.512 \, \, ^{\circ}\text{C} \cdot kg \cdot mol^{-1} \, \times 17.9 \cdot mol \cdot kg^{-1} = 9.17 \, ^{\circ}\text{C}$

5. Boiling point

$\rm T_{b} = T_{b}^{\circ} + \Delta T_{b} = 100.00 \, ^{\circ}\text{C} + 9.17 \, ^{\circ}\text{C} = \mathbf{109.17 \, ^{\circ}C}\\\rm \text{The boiling point of the solution is $\large \boxed{\mathbf{109.17 \, ^{\circ}C}}$}$

7 0

3 years ago

Which statement is true about how scientists draw conclusions from data?

jok3333 [9.3K]

I believe the answer is D.
Scientists are biased, and want to prove their specific hypothesis is right.

3 0

3 years ago

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